Artificial hand



Oct. 10, 1933. R TRAUTMAN 1,929,541

ARTIFICLAL HAND Filed Jan. 24, 1930 2 Sheets-Sheet l 5 Fig. 1

. 3 m: Rm] n\o I\C]. B. Tl emtmam Oct. 10, 1933. R B, TRAUTMAN 1,929,541

ARTIFICIAL HAND Filed Jan 24, 1930 2 Sheets-Sheet 2 Ray mend B. Tfmfmam dummy v and fingers when in closed position.

Patented Oct. 10, 1933 v TES:

, c i 'My invention relates to artificial hands and particularly to hands having fingers and thumbs articulated thereon and adapted conjointly -to open and close to grasp and hold objects in simulation -of=the human hand.

An object of. the invention resides in .providing separate means for operating the fingers and thumb and in individuallylocking the thumb .A still further object resides in effecting the locking ofthe thumb and fingers throughmemhers-fixedly attached to said thumb and fingers:

, Another object of the invention resides in pro-" vidingan arm for controllingvthe movement of the thumb and another arm for controlling the movement of the fingers. I

Another object "of'the invention resides in providing a pivoted finger frame. constructed with anactuating lever having -a cam' track for cooperation with its respective arm and in*simi-' larly providing-said thumb with a lever having a track for cooperation with the other arm.

A still furtherobjejct of the invention resides in the provision for locking saidfifing'ei's and: thumb against movement by means of said arms andlevers when said .arms are in finger and thumbclosing position. 1

An object of the invention resides :in constructing the lever for the finger frame with a cam surface and in providing the corresponding arm with a roller for engagement with said cam and, further,' to close said fingers by. throwing s aid lever in a direction causing it to coact with said cam and thereby swing thefinger frame in' finger closing direction.

Another object of the invention resides in providinga draw cord having a connection with saidarms for. shifting both thereof to move the. thumband the fingers conjointly; I

- A feature of the invention residesin connect ing the draw cord -to both arms; the connection 51 withone arm-being through a sheave mounted thereon'so as to produce a shifting connection ahd thus allow for compensation between 'theoperating. means for the thumb and fingers.

Oth'er objectsreside in the novel combination and arrangement'of parts, andin the details of construction hereinafter illustrated and/or described. 1 I Inthe drawings: I v. Fig.= 1 is a plan viewofanartificial hand illustrating an-embodiment of my invention, the removable'coverbeingi detached to disclose the interior' construction, the fingers being shown in closed position.:. i 1

Fig. 2is a view partlyin elevation and partly, in section of the hand shown in Fig.1. f Fig. .3. is. a View similar to Fig. 1 showing the fingers in open position. I .jFig. 4is' a view similar to Fig. 2 showing the fingers in open; position, The hand proper comprises a body member of wood or other suitable materialsimulating the metacarpus of the human hand. This body member. 10 isghollowed out to form a chamber 11 thereinfor the reception of the operating mechanism ofthe device; ,At'the wrist of the body member 10 is provided a threaded shank 33 by means of which thehand may be attached to the ordinary stump socket inthe customary manner. In the forwardportion of the body member 10 is formed an'opening '12 which communicates with, the. chamber 11,;and:at one side and ,towardthe lower part of the body member is formed a slot 13 which similarly communicates with the cham-; ber 11; I a The, thumb of the hand, designated atql, is constructed solid, preferably from the samematerial as thebody member 10 and is formed with a tongue '15 which is received within the slot 13 previously referred to. This thumb is articulated on the body member 10 in.a manner closely simulating the movement of the human thumb, a pintle 16in the member 10 passing through the tongue of thumb 14.

: "Informing the fingers 17, 18, 19 and 20 of the hand, I employ four spaced rods 21, 22, 23 a'nd24,

all of which are attached to a bar 25.common thereto, the rods and bar. constituting a finger frame. Mounted upon each of said rods is a finger body-650i a composition of rubber and the like. If desired, however, thefingers may be constructedof wood or other solid material, in which case the rods'need merely extend a short distance intothe butts of theifinger bodies.

" The bar25' to which the fingers of the hand are attached serves as a shaft for pivoting the" entire finger structure for movement in a direction toward and-from the thumb 14. This bar i's formed intermediatethe ends thereof with two vin on a pin 49. an elongated cam 50 secured to,but offsetfrom reduced annular portions 27 which are journaled in two bearings 28 and 29. These bearings are attached to a plate 30 by means of screws 31, said plate constituting a supporting frame for the finger structure andfor some of the operating parts of the hand. This plate 30 together with the bar 25 and appurtenant actuating parts extend into the opening 12 of the body member 10, the fingers extending from the body 10 in a natural manner, the actuating parts being disposed to permit of the operation thereof bymech anism contained within the chamber 11 of said body 10 of the hand. The screws 31, extending through the plate 30 and into the body member 10 of the hand, hold the bearings 28 and 29 and the said plate 30 in place; This plate is further secured to the handproper through an other screw 32 threaded into the body member 10.

Mechanism for operating the thumb l4 includes a lever 34 formed with a head 60 attached to the tongue 15 by screws 35 or. other suitable fastening means. A pintle 36 inserted into the body member 10 immediately below the plate 30 and passing thr'ough'an enlargement 11- 'of the chamber '11 thereof provides a pivotal mounting for a "swinging arm 37. Near the free end of this arm 3''! is a lug-38 which projects into and rides along a slot 39 formed longitudinally of the lever 34, said lug serving to depress or elevate the lever 34, according to the direction of movement of the arm '37, and, thereby cause the thumb '14 .to swing from its closed position as shown in Fig. 2 into its open position as shown in Fig. 4 or vice versa. The arm 37 is normally held in the posi- I tion shown in Figs. 2 and 4 by means of a spiral spring 40 encircling the pintle 36. Oneend of this spring is lodged in'an opening 41 in the arm 3'? and the other end thereof is hooked over the edge 'of the plate 30. This spring 40 is arranged to move the arm 37 toward the position shown in Fig. 2 thereby yieldingly forcing the thumb 14 into closed position. 'It is to be noted that due to the disposition and arrangement of parts, when the lug 38 is in 'theposition shown 'in Fig. 2, movement of the thumb 14 from itsclosed positionas by force applied to the thumb, is precludedthereby effecting a lock for holding the'thumbclosed.

However, upon a swinging movement of the arm 3'7 in a counter-clockwise direction as viewed in Figs. 2 and 4 and against the action of spring 40, the thumb may be readily swung into open position. The closing 'of the thumb is accomplished by releasing the arm 3'7,'the returnmovement of which is effected through the spring 40.

,In'mechanism for actuating the fingers 17, 18, 19 and 20, Iiemploy a bell-crank '43, which is pivoted on a screw 44 screwed into the plate 30 and into the body member 10. This bell-crank includes an arm 45 extending toward "the bar 25 and another arm 46 extending substantially parallel with saidbar and at right'angles to the arm 45. Said arm 45, 'forked at its free end, receives a small roller "48 which is journaled there! This roller 48 cooperates with the bar'25,'said cam forming a short lever through which'the finger frame is rocked in'finger closing direction and through which the reverse movement of said frame'is regulated. A cam surface 7 51 on cam contacts with the roller 48,-said surface extending generally in the directionof bar 25 and spiralling slightly. A spring 52, stretched over the bar 25 and frameplate 30, has one'end thereof caught on the'finger rod'22 and the other'e'nd thereof secured'to thearm 46of arm 46 of the bell crank 43.

tion with roller 48 upon a swinging movement of the arm 45 in a direction toward the thumb 14. Said spring 52 further effects a closing movement of the fingers by actuating the bell-crank 43 to swing the arm 45 in a direction away from the thumb and cause the roller 48, through the cam 50, to swing the finger frame. Two stops 54 and 55 limit the movement of the arm 45, so as to terminate the movement of the fingers, when in jfully open position and fully closed position.

,1 The thumb and fingers of the hand are operated through a draw cord 56 secured at one end 57 tothelower end 58 of the arm 37. This drawcord is looped about a sheave 59 journaled on a pintle 60 mounted in a--'fo'rked bracket 61 formed on the I H h A The draw cord 56 extends up through an opening 56 in the body member 10 of the hand and runsup along the arm of the user where it may be actuated in the ordinary manner as byhbeing looped about the shoulder.

The body 10 of the'hand may includeacover 62 capping the chamber '11 and enca'sing the plate 30 and mechanism attached thereto. Upon re' moval of this cover all of the operating parts of the hand become accessible.

7 In the use of the hand, the tension'ing of the draw cord causes the opening of the thumb and fingers. As this cord is tensioned, it exerts a backward pull upon the lever 37 and upon the arm 46, the sheave'59 on said arm '46 turning under the cord 'as need be in'a compensatingmanner. Thus, the backward movement of the lever 37 and arm 46 causes the opening or the fingers and thumb conjointly. Arm '45 engages the stop 55 when the fingers and *thu'mb have reached fully open position. Upon releasing the cord 56, the spring 52 and the spring 40 draw'the fingers and :thumb back into normally closed position causing the -same to grip and hold an object grasped by the hand. When the arms '37 and 45 reach closing position, as shown "in Figs. 1 and or somewhat nearly so, the lug 38 on the 'a'rm 37 is so disposed within the slot '39 of the 1eve'r e4 as to prevent the opening of the thumb 14 and to lock the-same closed and, at the same time, the roller 48 is disposed in relation to the cam surface-51M the cam 50 so as to hold the fingers 1'7, 18, 19 and 20 closed and locked. This per mits of using the hand for carrying baggage or performing other work where it i's'desirable to have a positive grip on the articles to prevent accidental opening of the hand and theconsequentreleasing of the objects held.

The advantages of my handare apparent. An extremely simple and positive device is provided, whereby articles may be conveniently and firmly grasped and held and manipulated in any desired manner. through members fixed relative thereto, thereby eliminating 'lost motion and reducing the number of elements through which'the'strain isftrans-' mitted. The mechanism is "so "designed as tobe readily confined within a space-such a'spermits of the construction of the hand. in simulation "of the human hand. Both the thumb-and fingers are coniointly operated through -a'singledraw cord and these members, when in closed position, are locked so 'as to prevent the unintentional opening of-th'e hand. A dual functioning spring. taking up play between parts, normally closes-the finger frame,'through the be1l-crank'48andcam The "fingers and. thumb are locked 50, and opens said frame, upon the tensioning of cord 56, under control of the coacting cam 50 and roller 48.

Changes in the specific form of my invention, as herein disclosed, may be made Twithin the scope of what is claimed without departing from the spirit of my invention.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

1. An artificial hand comprising a supporting structure, a finger pivoted to said supporting structure, an arm also pivoted thereto and movable in a plane containing the axis of the finger pivot, a lever on said finger forming an elongated track, and meanscarried by said arm for en gagement with said track to control the movementof said finger.

2. An artificial hand comprising a supporting structure, a finger pivoted to said supporting structure, a bell-crank pivoted to said structure and movable in the plane of the axis of the finger pivot, a lever on said finger presenting an elongated track, one of the arms of said bell-crank serving to engage said track to control the movement of said finger, and a spring connected to said finger and to the other arm of said bell-crank and operating to swing both thereof.

3. In an artificial hand, a body portion, a finger articulated thereon, a movable member mounted on said body portion and operating to swing the finger one way when moved in one direction and to control the retraction of said finger when moved in the opposite direction, a spring acting to move said member in said first direction, means operable against the action of said spring to retract said member, said spring serving further to retract said finger under the control of and during such retraction of said member.

4. An artificial hand comprising a supporting structure, a finger pivoted to said supporting structure, a lever attached to said finger and extending in the. direction of the axis of the pivot for said finger, an arm pivoted to said supporting structure for engagement with said lever at various localities along the length thereof, said arm being movable toward and from said lever to limit the position of the finger, means for moving said arm in one direction and resilient means for moving said arm in the other direction.

5. An artificial hand comprising a supporting structure, a finger pivoted to said supporting structure, an arm pivoted to said structure, a lever on said finger presenting an elongated track, said arm engaging said lever and movable along said track to control the movement of said finger and a spring connected to said finger and to said arm.

6. An artificial hand comprising a supporting structure, a finger pivoted to said supporting structure, a lever on said finger, an arm pivoted to said structure and. adapted to engage said lever to control the movement of said finger and a spring connected to said finger and to said arm.

finger for imparting movement from one thereof 7. An artificial hand comprising a supporting structure, a finger pivoted to said supporting structure, a lever on said finger presenting'an elongated track, an arm pivoted'to said supporting structure and having a portion movable along said track, and a spring connected to said finger and to-said arm for urging said arm against said track, said spring having a greater leverage upon said arm than on said finger to cause the arm to move along said track.

8. An artificial hand comprising a supporting structure, a finger pivoted to said supporting structure, an arm pivoted to said supporting structure, means disposed between said arm and to the other, said means including two contacting parts, and a spring eccentrically connected to said finger and arm, and operating to move said arm in one direction and to hold said parts in contact during the movement of the arm in such direction, and means for moving the arm.

9. An artificial hand comprising a supporting structure, a finger pivoted to said supporting structure, an arm pivoted to said supporting structure, meansdisposed between said arm and finger for imparting movement from one thereof to the other, said means including two contacting parts, and a spring eccentrically connected to said finger and arm, the eccentricity of said spring relative to the arm being greater than its eccentricity with respect to the finger to cause the arm to move in one direction, said spring holding the parts in contact during such movement and means for moving the arm.

10. In an artificial hand, a body portion, a no finger supporting bar axially rockable on said body portion, fingers mounted on said bar, a lever on said bar presenting an elongated cam surface extending generally in the direction of the axis of the bar, an arm pivoted on said body portion for endwise abutting contact with said lever along said cam surface, and means for swinging the arm, said arm through its cooperation with said lever, serving upon movement in one direction to I close the fingers and upon movement in the reo verse direction to control the opening of said fingers.

11. In an artificial hand, a body portion, a finger supporting bar axially rockable on said body portion, fingers mounted on said bar, cooperating cam elements, one mounted on said bar and one on said body portion, the latter being movably mounted, means for moving said latter element, said elementsxbeing adapted to contact with eachother along a line extending in the general direction of the axis of said bar and serving, upon movement of said second element in one direction to close said fingers and upon movement of said second element in the reverse direction to control the opening of said fingers.

RAYMOND B. TRAUTMAN. 

